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+### never forget
+* docker inspect [image]
+* docker history --no-capture [image]
+* docker run -it [image] /bin/sh
+* docker exec -it [image] /bin/sh
+* -p [HOST-port]:[CONTAINER-port] 
+  
+### DEBUG (rhel/centos) 
+* RUN yum install -y net-tools
+* RUN yum install -y procps